The Federal Aviation Administration has a plan for allowing drones to fly everywhere in the country. But research and regulations are months behind the schedule Congress set to have the unmanned devices fly safely with commercial airliners by September 2015.

FAA Administrator Michael Huerta released the five-year road map a month ago. It projected 7,500 unmanned aircraft would be in the skies within that period if regulations are in place.

But the FAA faces technical challenges, among them how much training to require of ground-based pilots, how to ensure that drones fly safely if they lose contact with their pilots and how drones and commercial aircraft should warn each other when they're in the same area.

"The FAA is committed to safe, efficient and timely integration of unmanned aircraft systems into our airspace," the agency said in a statement Monday. "Over the next several years the FAA will establish regulations and standards for the safe integration of remote piloted (unmanned aircraft) to meet increased demand."

The issue of commercial drones came to the forefront when Amazon CEO Jeff Bezos told CBS' 60 Minutes Sunday night that the online retail giant is testing the delivery of packages via drone.

The next step in the regulatory process is for Huerta to designate six experimental locations for researchers to test flying drones in general airspace. The agency received 25 proposals, and it's expected to announce its picks this month.

The FAA also hopes to release a proposed rule for small drones next year.

Despite the challenges, Michael Toscano, CEO of the Association of Unmanned Vehicle Systems International, welcomed the FAA plan. He said the industry is projected to create 100,000 jobs and generate $82 billion in economic activity in the decade after the aircraft are allowed in general airspace.

Drones are now severely limited. A hobbyist can fly a small aircraft several hundred feet off the ground. The FAA has approved several hundred permits for university research and public uses, including 80 law-enforcement agencies.

The research and regulations are already behind schedule. Under the congressional schedule set in February 2012, the six experimental locations were supposed to be named by August 2012 and the road map was due in February 2013.

The legislation called for drones to be fully integrated into the airspace by September 2015. Huerta insists that the FAA will meet the deadline.